METTL1 was negatively related to MSI and TMB in COAD, nevertheless it was positively correlated with the markers in HNSC, KICH, PRAD, and STAD, which manifested that METTL1 might possess an effect on the ICB therapeutic response in HNSC, KICH, PRAD, as well as STAD. The gene discussed is METTL1; the disease is colon adenocarcinoma.